So, I watched Half-Blood Prince again (yes, I'm a nerd), and it was drastically better the second time around. I'm still not going to claim that it's the best of the series, but it did become one of the better installments once I had the chance to sit back and enjoy it again.
I still feel that the movie is uneven because there is so much time spent on the angsty teenage love stories. The whole Ron-Lavender-Hermione love triangle started to wear a bit thin, and I could have done without a few of the scenes like the necklace/vomit scene. Sure, it was short but it was unnecessary and it chewed up valuable screen time.
Also, I felt that the Harry/Ginny relationship was awkward and forced. I knew it'd be tricky to pull off the subplot since a lot of it takes place in Harry's head, which is hard to translate to the screen, but some of the scenes were just odd (who ties someone's shoes?!?!). There were a few highlights though, like when he stands for her when she approaches the table, and I think the kiss was better than it was in the book.
I'm not against the romantic elements per se, but they just took up too much time which could have been spent on giving more of Tom Riddle's backstory (two memories were not enough), and more of the Half-Blood Prince mystery. The same can be said about the quidditch scenes. I've never been a huge fan of quidditch in the movies, so I was a little bummed that some of the more important plotlines were sacrificed in the end.
The end was also a little anticlimactic. I know that Yates decided against putting in the first Battle of Hogwarts to avoid repetition in Deathly Hallows, but the end needed an epic action sequence to set up Dumbledore's death. Instead we see him fall, the Death Eaters walk through the castle with zero resistance, and Harry gives a brief chase. Even the reaction to Dumbledore's death lacked something. Heck, Cedric's death seemed to affect people more than the Head Master's.
With all of that being said, I was won over by the movie because it had some well-timed humor that rivaled Goblet of Fire, and the story is still one of my favorites. Also, I was glad to see that most of Luna's appearances were kept in tact because she's hands down one of the best characters in the books.
I even like the tacked on attack on the Burrow. I know most purists probably didn't care for it, but I thought it worked perfectly because it makes the danger real. It's one thing to see the bridge collapse, but it's a totally different thing when you see these characters you have grown to care about be attacked in their own home. Plus, it added some well-timed suspense due to the fact that the Death Eaters were concealed by the field. Also, it's a good replacement for the wedding scene in Deathly Hallows since it's pretty clear that it's going to get cut.
Another positive was Alan Rickman's evolution as Snape. The character lost some of his edge in the movie, but Rickman's performance set up Snape's storyline in Deathly Hallows, and it will make him more sympathetic, which will make it easier for casual movie goers to get behind him. Kudos should also go to Jim Broadbent (Professor Slughorn) and Jessie Cave (Lavender Brown).
So, Half-Blood Prince is far from perfect (but which adaptation is perfect), but it has definitely moved up on my rankings of the films. Right now, it's neck and neck with Goblet of Fire, but I wouldn't be surprised if it makes a jump in the future.